Levosimendan limits reperfusion injury in a rat middle cerebral artery occlusion (MCAO) model

A New Approach in the Treatment of Traumatic Brain Injury: The Effects of Levosimendan on Necrosis, Apoptosis, and Oxidative Stress

OBJECTIVE

Traumatic brain injury (TBI) is an essential and common health problem worldwide. Levosimendan is an inotropic and vasodilator drug used to treat heart failure. Moreover, it exerts pleiotropic effects and, thus, protective effects on many organs. The present study aimed to investigate the effect of levosimendan on necrosis, apoptosis, and reactive oxygen species in rats with TBI.

METHODS

The study included 28 female Wistar-Albino rats weighing 200-250 g. The rats were divided into 4 groups with 7 rats each as follows: Group 1: No trauma group (Control), Group 2: Traumatized, untreated group (T), Group 3: Levosimendan was administered at a dose of 12 μg/kg intraperitoneally 1 hour after the trauma (L1), Group 4: Levosimendan was administered at a dose of 12 μg/kg intraperitoneally 2 hours after the concussion (L2). After the experiment, the rats were decapitated, and the brain tissue was removed. Necrosis was assessed with Cresyl violet staining, apoptosis was assessed with immunohistochemical analysis, superoxide dismutase and catalase levels were measured with the spectrophotometric method, and malondialdehyde (MDA) levels were assessed by High-Performance Liquid Chromatography.

RESULTS

The number of necrotic cells in the L1 and L2 groups was significantly lower than in the K and T groups (P = 0.015 and P = 0.03, respectively). Although the active caspase-3 level was signified considerably in the T, L1, and L2 groups compared to the K group, no significant difference was found among these 3 groups (P > 0.05). The results of superoxide dismutase levels were similar to those of active caspase-3. catalase level was significantly higher in the K group than in the T and L2 groups (P = 0.045). Malondialdehyde activity was considerably higher in the L1 and L2 groups compared to the K group (P = 0.023).

CONCLUSIONS

Our results indicated that levosimendan may exert a neuroprotective effect by reducing necrosis in TBI and that levosimendan does not affect apoptosis and antioxidant levels in TBI. Comprehensive studies are needed to elucidate the effect of levosimendan on TBI fully.

The Use of Levosimendan for the Treatment of Heart Failure and its Potential Organoprotective Effects

The review article is aimed at providing a recent update on the use of levosimendan, an inotropic drug in current use for the treatment of heart failure. The review discusses its mechanisms of action, main hemodynamic effects, clinical trials and obtained evidences that have formed the basis of the current guidelines on its use, as well as the latest clinical and experimental trials evaluating its organ-protective effects. Conclusion: levosimendan has a promising potential for treating heart failure, prescribed even in low doses, and may be regarded as a drug with cerebroprotective and possible nephroprotective effects, requiring further large randomized clinical trials.

Neuroprotective Effect of Piclamilast-Induced Post-Ischemia Pharmacological Treatment in Mice

Various studies have evidenced the neuroprotective role of PDE4 inhibitors. However, whether PDE4 inhibitor, Piclamilast pharmacological post-treatment is protective during cerebral ischemia reperfusion-induced injury remains unknown. Therefore, this study design included testing the hypothesis that Piclamilast administered at the beginning of a reperfusion phase (Piclamilast pPost-trt) shows protective effects and explores & probes underlying downstream mechanisms. Swiss albino male mice were subjected to global ischemic and reperfusion injury for 17 min. The animals examined cerebral infarct size, biochemical parameters, inflammatory mediators, and motor coordination. For memory, assessment mice were subjected to morris water maze (MWM) and elevated plus maze (EPM) test. Histological changes were assessed using HE staining. Piclamilast pPost-trt significantly reduced I/R injury-induced deleterious effects on biochemical parameters of oxidative stress, inflammatory parameters, infarct size, and histopathological changes, according to the findings. These neuroprotective effects of pPost-trt are significantly abolished by pre-treatment with selective CREB inhibitor, 666-15. Current study concluded that induced neuroprotective benefits of Piclamilast Post-trt, in all probability, maybe mediated through CREB activation. Hence, its neuroprotective effects can be further explored in clinical settings.

Levosimendan increases brain tissue oxygen levels after cardiopulmonary resuscitation independent of cardiac function and cerebral perfusion

Prompt reperfusion is important to rescue ischemic tissue; however, the process itself presents a key pathomechanism that contributes to a poor outcome following cardiac arrest. Experimental data have suggested the use of levosimendan to limit ischemia–reperfusion injury by improving cerebral microcirculation. However, recent studies have questioned this effect. The present study aimed to investigate the influence on hemodynamic parameters, cerebral perfusion and oxygenation following cardiac arrest by ventricular fibrillation in juvenile male pigs. Following the return of spontaneous circulation (ROSC), animals were randomly assigned to levosimendan (12 µg/kg, followed by 0.3 µg/kg/min) or vehicle treatment for 6 h. Levosimendan-treated animals showed significantly higher brain PbtO₂ levels. This effect was not accompanied by changes in cardiac output, preload and afterload, arterial blood pressure, or cerebral microcirculation indicating a local effect. Cerebral oxygenation is key to minimizing damage, and thus, current concepts are aimed at improving impaired cardiac output or cerebral perfusion. In the present study, we showed that NIRS does not reliably detect low PbtO₂ levels and that levosimendan increases brain oxygen content. Thus, levosimendan may present a promising therapeutic approach to rescue brain tissue at risk following cardiac arrest or ischemic events such as stroke or traumatic brain injury.

Intranasal levosimendan prevents cognitive dysfunction and apoptotic response induced by repeated isoflurane exposure in newborn rats

Anesthetic-induced toxicity in early life may lead to risk of cognitive decline at later ages. Notably, multiple exposures to isoflurane (ISO) cause acute apoptotic cell death in the developing brain and long-term cognitive dysfunction. This study is the first to investigate whether levosimendan (LVS), known for its protective myocardial properties, can prevent anesthesia-induced apoptotic response in brain cells and learning and memory impairment. Postnatal day (P)7 Wistar albino pups were randomly assigned to groups consisting of an equal number of males and females in this laboratory investigation. We treated rats with LVS (0.8 mg/kg/day) intranasally 30 min before each ISO exposure (1.5%, 3 h) at P7+9+11. We selected DMSO as the drug vehicle. Also, the control group at P7+9+11 received 50% O2 for 3 h instead of ISO. Neuroprotective activity of LVS against ISO-induced cognitive dysfunction was evaluated by Morris water maze. Expression of apoptotic-related proteins was detected in the whole brain using western blot. LVS pretreatment significantly prevented anesthesia-induced deficit in spatial learning (at P28-32) and memory (at P33, P60, and P90). No sex-dependent difference occurred on any day of the training and probe trial. Intranasal LVS was also found to significantly prevent the ISO-induced apoptosis by reducing Bax and cleaved caspase-3, and by increasing Bcl-2 and Bcl-xL. Our findings support pretreatment with intranasal LVS application as a simple strategy in daily clinical practice in pediatric anesthesia to protect infants and children from the risk of general anesthesia-induced cell death and cognitive declines.

Reduced Amygdala Microglial Expression of Brain-Derived Neurotrophic Factor and Tyrosine Kinase Receptor B (TrkB) in a Rat Model of Poststroke Depression

Background

Previous studies have implicated reduced brain-derived neurotrophic factor (BDNF) expression and BDNF-TrkB receptor signaling as well as microglial activation and neuroinflammation in poststroke depression (PSD). However, the contributions of microglial BDNF-TrkB signaling to PSD pathogenesis are unclear.

Material/Methods

We compared depression-like behaviors as well as neuronal and microglial BDNF and TrkB expression levels in the amygdala, a critical mood-relating limbic structure, in rat models of stroke, depression, and PSD. Depression-like behaviors were assessed using the sucrose preference test, open-field test, and weight measurements, while immunofluorescence double staining was employed to estimate BDNF and TrkB expression by CD11b-positive amygdala microglia and NeuN-positive amygdala neuron. Another group of PSD model rats were examined following daily intracerebroventricular injection of proBDNF, tissue plasminogen activator (t-PA), or normal saline (NS) for 7 days starting 4 weeks after chronic unpredictable mild stress (CUMS).

Results

The numbers of BDNF/CD11b- and TrkB/CD11b-immunofluorescence-positive cells were lowest in the PSD group at 4 and 8 weeks after CUMS (P<0.05). PSD rats also showed reduced weight, sucrose preference, locomotion, and rearing compared with controls (P<0.05). The coexpression of BDNF/NeuN- and TrkB/NeuN-positive cells were not significantly different between groups at 4 and 8 weeks after CUMS (P>0.05). Injection of t-PA increased BDNF/CD11b- and TrkB/CD11b-positive cells in the amygdala of PSD rats and normalized behavior compared with NS or proBDNF injection (P<0.05). In contrast, proBDNF injection reduced BDNF and TrkB expression compared with NS (P<0.05).

Conclusions

These results suggest that decreased BDNF and TrkB expression by amygdala microglia may contribute to PSD pathogenesis and depression-like behaviors.

Pharmacological postconditioning: a molecular aspect in ischemic injury

OBJECTIVE

Ischaemia/reperfusion (I/R) injury is defined as the damage to the tissue which is caused when blood supply returns to tissue after ischaemia. To protect the ischaemic tissue from irreversible injury, various protective agents have been studied but the benefits have not been clinically applicable due to monotargeting, low potency, late delivery or poor tolerability.

KEY FINDINGS

Strategies involving preconditioning or postconditioning can address the issues related to the failure of protective therapies. In principle, postconditioning (PoCo) is clinically more applicable in the conditions in which there is unannounced ischaemic event. Moreover, PoCo is an attractive beneficial strategy as it can be induced rapidly at the onset of reperfusion via series of brief I/R cycles following a major ischaemic event or it can be induced in a delayed manner. Various pharmacological postconditioning (pPoCo) mechanisms have been investigated systematically. Using different animal models, most of the studies on pPoCo have been carried out preclinically.

SUMMARY

However, there is a need for the optimization of the clinical protocols to quicken pPoCo clinical translation for future studies. This review summarizes the involvement of various receptors and signalling pathways in the protective mechanisms of pPoCo.

Synergistic Effects of Moderate Therapeutic Hypothermia and Levosimendan on Cardiac Function and Survival After Asphyxia-Induced Cardiac Arrest in Rats

Background

This study investigated whether levosimendan, an inotropic calcium sensitizer, when combined with moderate therapeutic hypothermia, may exert synergistic benefits on post–cardiac arrest myocardial dysfunction and improve outcomes.

Methods and Results

After 9.5‐minute asphyxia‐induced cardiac arrest and resuscitation, 48 rats were randomized equally into 4 groups following return of spontaneous circulation (ROSC), including normothermia, hypothermia, normothermia–levosimendan, and hypothermia–levosimendan groups. For the normothermia group, the target temperature was 37°C while for the hypothermia group, the target temperature was 32°C, both of which were to be maintained for 4 hours after ROSC. Levosimendan was administered after ROSC with a loading dose of 10 μg/kg and then infused at 0.1 μg/kg per min for 4 hours. In the hypothermia–levosimendan group, left ventricular systolic function and cardiac output increased significantly, whereas the heart rate and systemic vascular resistance decreased significantly compared with the normothermia group. Also, the concentrations of interleukin 1β at 4 hours post‐ROSC and the production of NO between 1 hour and 4 hours post‐ROSC were reduced significantly in the hypothermia–levosimendan group compared with the normothermia group. The 72‐hour post‐ROSC survival and neurological recovery were also significantly better in the hypothermia–levosimendan group compared with the normothermia group (survival, 100% versus 50%, χ² test, P=0.006).

Conclusions

Compared with normothermia, only combined moderate therapeutic hypothermia and levosimendan treatment could consistently improve post–cardiac arrest myocardial dysfunction and decrease the release of pro‐inflammatory molecules, thereby improving survival and neurological outcomes. These findings suggest synergistic benefits between moderate therapeutic hypothermia and levosimendan.

Effects of resveratrol postconditioning on cerebral ischemia in mice: role of the sirtuin-1 pathway

Evidence has demonstrated that resveratrol preconditioning exhibits neuroprotection against cerebral ischemia-reperfusion (IR) injury. The current investigation aimed to explore whether pharmacological postconditioning, by administering resveratrol, after a sustained ischemia and prior to prolonged reperfusion abrogates cerebral IR injury. Cerebral IR-induced injury mice model was employed in this study to evaluate the neuroprotective effects of pharmacological postconditioning with resveratrol (30 mg/kg; i.p.) administered 5 min before reperfusion. We administered sirtinol, a SIRT1/2 selective inhibitor (10 mg/kg; i.p.) 10 min before ischemia (17 min) and reperfusion (24 h), to elucidate whether the neuroprotection with resveratrol postconditioning depends on SIRT1 activation. Various biochemical and behavioural parameters and histopathological changes were assessed to examine the effect of pharmacological postconditioning. Infarct size is estimated using TTC staining. It was established that resveratrol postconditioning abrogated the deleterious effects of IR injury expressed with regard to biochemical parameters of oxidative stress (TBARS, SOD, GSH), acetylcholinesterase activity, behavioural parameters (memory, motor coordination), infarct size, and histopathological changes. Sirtinol significantly reversed the effect of resveratrol postconditioning. We conclude that induced neuroprotective benefits of resveratrol postconditioning may be the consequence of SIRT1 activation and resveratrol can be considered, for further studies, as potential agent inducing pharmacological postconditioning in clinical situations.

Neuroprotective effect of pharmacological postconditioning on cerebral ischaemia-reperfusion-induced injury in mice

OBJECTIVES

To investigate the mechanism of neuroprotection rendered via pharmacological postconditioning in cerebral ischaemia-reperfusion-induced injury in mice.

METHODS

Pharmacological postconditioning is strategy which either involves hindering deleterious pathway or inducing modest stress level which triggers intracellular defence pathway to sustain more vigorous insult leading to conditioning. Hence, in current research we explored the potentiality of CGS21680 (0.5 mg/kg; i.p), an adenosine A₂ A receptor agonist and PTEN inhibitor, SF1670 (3 mg/kg; i.p.) to trigger postconditioning after inducing cerebral global ischaemia (17 min) and reperfusion (24 h)-induced injury via occlusion of both carotid arteries. Mice were also given treatment with LY294002 (1.5 mg/kg; i.p.), a PI3K inhibitor and adenosine A₂ A receptor antagonist, Istradefylline (2 mg/kg; i.p.), to establish the precise mechanism of postconditioning. Various biochemical and behavioural parameters were assessed to examine the effect of pharmacological postconditioning.

KEY FINDINGS

Pharmacological postconditioning induced with CGS21680 and SF1670 attenuated the infarction along with improved behavioural and biochemical parameters in comparison with ischaemia-reperfusion control group. The outcome of postconditioning with CGS21680 and SF1670 was significantly reversed by LY294002 and Istradefylline, respectively.

CONCLUSIONS

The neuroprotective effects of CGS21680 and SF1670 postconditioning on cerebral ischaemia-reperfusion injury may be due to PI3K/Akt pathway activation.

Microarray Data Analysis of Molecular Mechanism Associated with Stroke Progression

This study aimed to explore the molecular mechanism of stroke and provide a new target in the clinical management. The miRNA dataset GSE97532 (3 blood samples from middle cerebral artery occlusion (MCAO) and 3 from sham operation) and mRNA dataset GSE97533 (3 blood samples from MCAO and 3 from sham operation) were obtained from GEO database. Differentially expressed mRNA (DEGs) and miRNAs (DEMIRs) were screened out between MCAO and sham operation groups. Then, DEMIR-DEG interactions were explored and visualized using Cytoscape software. Moreover, the enrichment analysis was performed on these DEMIRs and DEGs. Furthermore, protein-protein interaction (PPI) network was constructed. Finally, the DEG-target transcription factors (TFs) were investigated using the WebGestal software. The current bioinformatics analysis revealed 38 DEMIRs and 546 DEGs between MCAO and sham operation groups. The DEMIR-DEG analysis revealed 370 relations, such as miR-107-5p-Furin. The top 10 up- and downregulated DEMIRs were mainly enriched in pathways like cAMP signaling pathway. The PPI network analysis revealed 2 modules. The target DEGs of the 10 up- and downregulated DEMIRs in 2 modules were mainly assembled in functions like ATP binding and pathway including ABC transporters. Furthermore, the DEG-TF network analysis identified 5 outstanding TFs including androgen receptor (AR). miR107-5p might take part in the progression of stroke via inhibiting the expression of Furin. TFs like AR might be used as a novel gene therapy target for stroke. Furthermore, cAMP signaling pathway and ATP binding function might be a novel breakthrough for stroke treatment.

Levosimendan exerts anticonvulsant properties against PTZ-induced seizures in mice through activation of nNOS/NO pathway: Role for KATP channel

AIMS

Although approving new anticonvulsants was a major breakthrough in the field of epilepsy control, so far we have met limited success in almost one third of patients suffering from epilepsy and a definite and reliable method is yet to be found. Levosimendan demonstrated neuroprotective effects and reduced mortality in conditions in which seizure can be an etiology of death; however, the underlying neuroprotective mechanisms of levosimendan still eludes us. In the light of evidence suggesting levosimendan can be a K_ATP channel opener and nitrergic pathway activator, levosimendan may exert antiseizure effects through K_ATP channels and nitrergic pathway.

MAIN METHODS

In this study, the effects of levosimendan on seizure susceptibility was studied by PTZ-induced seizures model in mice.

KEY FINDINGS

Administration of a single effective dose of levosimendan significantly increased seizures threshold and the nitrite level in the hippocampus and temporal cortex. Pretreatment with noneffective doses of glibenclamide (a K_ATP channel blocker) and L-NAME (a non-selective NOS inhibitor) neutralize the anticonvulsant and nitrite elevating effects of levosimendan. While 7-NI (a neural NOS inhibitor) blocked the anticonvulsant effect of levosimendan, Aminoguanidine (an inducible NOS inhibitor) failed to affect the anticonvulsant effects of levosimendan. Cromakalim (a K_ATP channel opener) or l-arginine (an NO precursor) augmented the anticonvulsant effects of a subeffective dose of levosimendan. Moreover, co-administration of noneffective doses of Glibenclamide and L-NAME demonstrated a synergistic effect in blocking the anticonvulsant effects of levosimendan.

SIGNIFICANCE

Levosimendan has anticonvulsant effects possibly via K_ATP/nNOS/NO pathway activation in the hippocampus and temporal cortex.

Levosimendan, a new therapeutic approach to prevent delayed cerebral vasospasm after subarachnoid hemorrhage?

BACKGROUND

Under physiological cerebral conditions, levosimendan, a calcium-channel sensitizer, has a dose-dependent antagonistic effect on prostaglandin F2alpha (PGF)-induced vasoconstriction. This circumstance could be used in antagonizing delayed cerebral vasospasm (dCVS), one of the main complications after subarachnoid hemorrhage (SAH), leading to delayed cerebral ischemia and ischemic neurological deficits. Data already exist that identified neuroprotective effects of levosimendan in a traumatic brain injury model and additionally, it has been proven that this compound prevents narrowing of the basilar artery (BA) luminal area after SAH in an in vitro rabbit model. Takotsubo cardiomyopathy, a severe ventricular dysfunction, is also a well-known complication after SAH, associated with pulmonary edema and prolonged intubation.

METHODS

The polypeptide endothelin-1 (ET-1) plays a key role in the development of dCVS after SAH. Therefore, the aim of the present investigation was to detect functional interactions between the calcium-sensitizing and the ET-1-dependent vasoconstriction after experimental-induced SAH; interactions between levosimendan and a substrate-specific vasorelaxation in the BA were also examined. It was reviewed whether levosimendan has a beneficial influence on endothelin(A) and/or endothelin(B₁) receptors (ET-(A) and ET-(B₁) receptors) in cerebral vessels after SAH. We also examined whether this drug could have antagonistic effects on a PGF-induced vasoconstriction.

RESULTS

Under treatment with levosimendan after SAH, the endothelin system seems to be affected. The ET-1-induced contraction is decreased, not significantly. In addition, we detected changes in the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway. Preincubation with levosimendan causes a modulatory effect on the ET-(B₁) receptor-dependent vasorelaxation. It induces an upregulation of the NO-cGMP pathway with a significantly increased relaxation. Even after PGF-induced precontraction a dose-dependent relaxation was registered, which was significantly higher (E_max) and earlier (pD₂) compared to the concentration-effect curve without levosimendan.

CONCLUSIONS

After experimental-induced dCVS, levosimendan seems to restore the well-known impaired function of the vasorelaxant ET-(B₁) receptor. Levosimendan also reversed the PGF-induced contraction dose-dependently. Both of these mechanisms could be used for antagonizing dCVS in patients suffering SAH. Levosimendan could even be used additionally in treating patients developing takotsubo cardiomyopathy.

Ischemic conditions and ß-secretase activation: The impact of membrane cholesterol enrichment as triggering factor in rat brain endothelial cells

Among harmful conditions damaging the blood–brain barrier, cerebral stroke and reperfusion injuries were proposed as contributing factors to Alzheimer's disease etiology. Indeed it was reported that ischemic conditions promote β-amyloid peptide production in brain endothelial cells, although implicated mechanisms are yet not fully understood.Oxidative injury related to ischemia affects membrane-lipids profile by altering their biochemical properties and structural dynamics, which are also believed to play significant role in the amyloid precursor protein processing, suggesting a link between alterations in lipid membrane composition and β-amyloid peptide production enhancement.Using brain microvascular endothelial cells, here we demonstrate how oxygen and glucose deprivation followed by normal conditions restoration, mimicking ischemic environment, increases cell cholesterol amount (+20%), reduces membrane fluidity and results in strong activation (+40%) of β-secretase 1 enzymatic activity. Moreover, we observed an increase of amyloid precursor protein and β-secretase 1 protein levels with altered localization in non-discrete (Triton X-100 soluble) membrane domains, leading to an enhanced production of amyloid precursor protein β-carboxyl-terminal fragment. Therefore, lipid alterations induced by oxygen and glucose deprivation enhance β-secretase 1 activity, favor its proximity to amyloid precursor protein and may concur to increased amyloidogenic cleavage. The latter, represents a detrimental event that may contribute to β-amyloid homeostasis impairment in the brain and to Alzheimer's disease-related BBB dysfunctions.

Role of PiCCO monitoring for the integrated management of neurogenic pulmonary edema following traumatic brain injury: A case report and literature review

Neurogenic pulmonary edema (NPE) is occasionally observed in patients with traumatic brain injury (TBI); however, this condition is often underappreciated. NPE is frequently misdiagnosed due to its atypical clinical performance, thus delaying appropriate treatment. A comprehensive management protocol of NPE in patients with TBI has yet to be established. The current study reported the case of a 67-year-old man with severe TBI who was transferred to our intensive care unit (ICU). On day 7 after hospitalization, the patient suddenly suffered tachypnea, tachycardia, systemic hypertension and hypoxemia during lumbar cistern drainage. Intravenous diuretics, tranquilizer and glucocorticoid were administered due to suspected left heart failure attack. Chest radiography examination supported the diagnosis of pulmonary edema; however, hypotension and hypovolemia were subsequently observed. Pulse index continuous cardiac output (PiCCO) hemodynamic monitoring and bedside echocardiography were performed, which excluded the diagnosis of cardiac pulmonary edema, and thus the diagnosis of NPE was confirmed. Goal-directed therapy by dynamic PiCCO monitoring was then implemented. In addition, levosimendan, an inotropic agent, was introduced to improve cardiac output. The patient had complete recovered from pulmonary edema and regained consciousness on day 11 of hospitalization. The current case demonstrated that PiCCO monitoring may serve a central role in the integrated management of NPE in patients with TBI. Levosimendan may be a potential medicine in treating cardiac dysfunction, along with its benefit from improving neurological function in NPE patients.

Levosimendan beyond inotropy and acute heart failure: Evidence of pleiotropic effects on the heart and other organs: An expert panel position paper

Levosimendan is a positive inotrope with vasodilating properties (inodilator) indicated for decompensated heart failure (HF) patients with low cardiac output. Accumulated evidence supports several pleiotropic effects of levosimendan beyond inotropy, the heart and decompensated HF. Those effects are not readily explained by cardiac function enhancement and seem to be related to additional properties of the drug such as anti-inflammatory, anti-oxidative and anti-apoptotic ones. Mechanistic and proof-of-concept studies are still required to clarify the underlying mechanisms involved, while properly designed clinical trials are warranted to translate preclinical or early-phase clinical data into more robust clinical evidence. The present position paper, derived by a panel of 35 experts in the field of cardiology, cardiac anesthesiology, intensive care medicine, cardiac physiology, and cardiovascular pharmacology from 22 European countries, compiles the existing evidence on the pleiotropic effects of levosimendan, identifies potential novel areas of clinical application and defines the corresponding gaps in evidence and the required research efforts to address those gaps.

[Use of levosimendan in children]

Levosimendan is a calcium-sensitizing drug with positive inotropic properties. As an inodilator, this molecule also has a vasodilation effect. While its efficacy has been demonstrated in the adult in the context of cardiac surgery, its pediatric use is still not widespread. Many studies have shown its safety of use in children, including in the newborn. Across the world, a growing number of teams use levosimendan to treat both acute and chronic heart failure. Through a review of the literature, we describe its pharmacodynamic effects, its current applications, and its perspectives of use in children.

Levosimendan Improves Neurological Outcome in a Swine Model of Asphyxial Cardiac Arrest

BACKGROUND

In asphyxial cardiac arrest, the severe hypoxic stress complicates the resuscitation efforts and results in poor neurological outcomes. Our aim was to assess the effects of levosimendan on a swine model of asphyxial cardiac arrest.

METHODS

Asphyxial cardiac arrest was induced in 20 Landrace/Large White piglets, which were subsequently left untreated for four minutes. The animals were randomised to receive adrenaline alone (n=10, Group A) and adrenaline plus levosimendan (n=10, Group B). All animals were resuscitated according to the 2010 European Resuscitation Council guidelines. Haemodynamic variables were measured before arrest, during arrest and resuscitation, and during the first 30 minutes after return of spontaneous circulation (ROSC), while survival and neurologic alertness score were measured 24 hours later.

RESULTS

Return of spontaneous circulation was achieved in six animals (60%) from Group A and nine animals (90%) from Group B (p=0.303). During the first minute of cardiopulmonary resuscitation, coronary perfusion pressure was significantly higher in Group B (p=0.046), but there was no significant difference at subsequent time points until ROSC. Although six animals (60%) from each group survived after 24 hours (p=1.000), neurologic examination was significantly better in the animals of Group B (p<0.01).

CONCLUSIONS

The addition of levosimendan to adrenaline improved coronary perfusion pressure immediately after the onset of cardiopulmonary resuscitation and resulted in better 24-hour neurological outcome.

Levosimendan alone and in combination with valsartan prevents stroke in Dahl salt-sensitive rats

The effects of levosimendan on cerebrovascular lesions and mortality were investigated in models of primary and secondary stroke. We aimed to determine whether the effects of levosimendan are comparable to and/or cumulative with those of valsartan, and to investigate whether levosimendan-induced vasodilation has a role in its effects on stroke. In a primary stroke Dahl/Rapp rat model, mortality rates were 70% and 5% for vehicle and levosimendan, respectively. Both stroke incidence (85% vs. 10%, P<0.001) and stroke-associated behavioral deficits (7-point neuroscore: 4.59 vs. 5.96, P<0.001) were worse for vehicle compared to levosimendan. In a secondary stroke model in which levosimendan treatment was started after cerebrovascular incidences were already detected, mean survival times were 15 days with vehicle, 20 days with levosimendan (P=0.025, vs. vehicle), 22 days with valsartan (P=0.001, vs. vehicle), and 31 days with levosimendan plus valsartan (P<0.001, vs. vehicle). The respective survivals were 0%, 16%, 20% and 59%, and the respective incidences of severe lesions were 50%, 67%, 50% and 11%. In this rat model, levosimendan increased blood volume of the cerebral vessels, with significant effects in the microvessels of the cortex (∆R=3.5±0.15 vs. 2.7±0.17ml for vehicle; P=0.001) and hemisphere (∆R=3.2±0.23 vs. 2.6±0.14ml for vehicle; P=0.018). Overall, levosimendan significantly reduced stroke-induced mortality and morbidity, both alone and with valsartan, with apparent cumulative effects, an activity in which the vasodilatory effects of levosimendan have a role.

Oral Levosimendan Increases Cerebral Blood Flow Velocities in Patients with a History of Stroke or Transient Ischemic Attack: A Pilot Safety Study

Background

Intravenous levosimendan is indicated for acute heart failure. The compound has shown promising beneficial effects in ischemic stroke models.

Objective

We evaluated the efficacy and safety of oral levosimendan in patients with a history of cerebral ischemia.

Methods

In a randomized, double-blind, placebo-controlled, parallel-group study, 16 patients with a history of ischemic stroke/transient ischemic attack received oral levosimendan in 5 escalating doses from 0.125 to 2.0 mg daily for 18-day intervals of each dose; 5 patients received placebo. Twenty-four-hour ambulatory ECG and cerebral blood flow velocities using transcranial Doppler ultrasound were recorded at baseline and at the end of each dosing period. Vasomotor reactivity was assessed via the breath holding index. In addition, plasma levels of N-terminal-pro-B-type natriuretic peptide (NT-pro-BNP) and the metabolites of levosimendan were determined.

Results

Levosimendan induced an increase in cerebral blood flow velocities and a decrease in NT-pro-BNP compared with placebo. There was no significant effect on breath holding index. Doses ≥0.5 mg increased heart rate by 5 to 9 beats/min. The dose level of 2.0 mg exceeded the preset safety margin of ventricular extrasystoles per hour (ie, upper 90% CI of the ratio of levosimendan to placebo above 2) with an estimate of 3.10 (90% CI, 0.95–10.07).

Conclusions

Oral levosimendan increases cerebral blood flow velocities and diminishes NT-pro-BNP levels in patients with earlier ischemic cerebrovascular event. Daily doses up to 1.0 mg were well tolerated, whereas the 2.0 mg dose level induced an increase in ventricular extrasystoles. ClinicalTrials.gov identifier: NCT00698763.

The role of Levosimendan in cardiopulmonary resuscitation

Although initial resuscitation from cardiac arrest (CA) has increased over the past years, long term survival rates remain dismal. Epinephrine is the vasopressor of choice in the treatment of CA. However, its efficacy has been questioned, as it has no apparent benefits for long-term survival or favorable neurologic outcome. Levosimendan is an inodilator with cardioprotective and neuroprotective effects. Several studies suggest that it is associated with increased rates of return of spontaneous circulation as well as improved post-resuscitation myocardial function and neurological outcome. The purpose of this article is to review the properties of Levosimendan during cardiopulmonary resuscitation (CPR) and also to summarize existing evidence regarding the use of Levosimendan in the treatment of CA.